Dead locking latch



Oct. 16, 1928. 1,688,240

H. w. KEIGWIN DEAD LOCKING LATCH Filed NOV. 29, 1927 hgl- /5529 z '-25 ,2 l/fflg" 5 621-17- 0 f/ /60 R 8 l: f3 2a /J il :fn

f listened oct. 16, 192s.

uNl'rEDsTA TES PATENT of .mY w. KEIGWIN, 0F MOUN T VERNON, NEW YORK.

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FICE;

i 'DEAD Looms LATCH.

` aptuuaaalea inventarse, 1927.' seria; No. escasa This invention relates to latches and has for its principal object the provision of a latch which will insure privacy` when desired. A further objectA ofl the inventioirliesn theV provision of 'a latchwhich'.Y when the `door isl closed from the inside can fonlyrbe operated from the inside but whendthe door isfclosed from the outside the door either side. p f, j

While the primary use of the latch of this type may perhaps be in connection `with toll'et rooms, private offices or telephone booths, the invention is not limited to such use nor inany waylother than by the claims themselves as the particular structure illustrated `may, be much altered without departing from the'.l spirit of my invention. e y v, It frequently happens that privacy 1s' de-` sired at certain times, for example, in abath-v room, but with some automatic arrangement whereby the bathroom is available to'alnyonel else when not occupied and without the need of providing a latchor key operated lock, 1n other words, 'permitting the very simple latch of the present linvention to replace themuch more complicated locks now in use.

Figure'l is aview of cover plate removed.l

f'fplate withthe'associated partsH-"xf 4o bac Figre3iis. a'centralcrossjsectionthm the latchjf -v "Figure 4 isalview similar to'Figure 1 but showing the. bolt incaughtpo sition I e Figure is a detail showing particularly theguidngpin f Figure 6 is a view ofthe Lside collar.

Figure -7 is a perspective o the outside roll 8 is amodited form-ouf roll back in.

whichn the vusual cam is replaced part by an arc.

. 'The housing 10 preferably permanently;

-21 having a preferably integral socket 22j since the depth of this socket is an importantdetail and it is therefore best not to use a fiat sheet which however, would be satisfactory provided that the mechanic made therecess in the woodwork ofthe j amb thev proper depth. i

Y 4 I'emov'ableside plate 12. may be opened,4 from be. described later.'

formed in the rear 'In conformity with .room and Aknob has The bolt has a central elongated recess 25 1 and ends rearwardly in a yoke having similar arms26 each ending in an inwardly directed transverse lug 27 and a shorter outwardly directed lug 28, the latter preferably each/havlng a guiding pin 29v adapted to engage the- The outer doorknob 30 asslng thru a. pivote has ashaft or spin; die 31 which extends slightly less than halfl wayinto the housing" slightly bowed out centrally for a purpose to 'f vThe lower side of the outer-collar has a niche 36 which is engaged byv a pm 37 on a 'spring 38 anchored -to the Vside plate as by the screw 39, which pin holds the square shaft of the outside knob 30 so that two of its faces 'are horizontal, the spring 38 movement of the outsidel nob 30 and the pin 37 forming a stop in eldingly resisting' both directions.

The inside collar 40 has a m11 back 41ste also a cam 42either integral or ermanently secured vto 'it' or, expressed dilerently, the roll back has-an integral collar for pivoting the shanl'c44V of the inside knob 45 and also has the cam surface for operating the 'outside roll back50 which has an angu1a`lug'514 which is engaged by the cam 42 and also has a rearwardly extending lug 53 which may be moved into olding engagement with a recess outside;k roll .back has aslot 54 which slidably but somewhat snugly engages the shaft 31. whileone or the` other of the shoulders 55 withdraws the bolt 20 against the bolt spring 61 when'the outer knob and shaft are rotated. the usual custom this spring-61 is confined in the slot 25 of the bolt, is positioned by the anchoring projection 62 of the housing.- Thev and engages the stud 15 which is an in-t tepalpart of the housing. suming that the door is closed, been shut from the outside: The the outside is now turned either having last tothe right -or left, it makes no diiference, andthe door is swung outward so that when the knob is released the parts assume the positions shown in he operation of the device is as followsasknobv 30 on ,igure 1 with the bolt 20 projecting its full extent. The operator nowv goes inside the turning the knob or not as he desires. If vthe not been turned when the door was closedthe parts,

pulls the door shut by the knob 45,

that the lugs 27 and 28 will not touch the roll back shoulders but will be positioned nearer to the rear of the casing 1 0, that is, toward the recess 60, and privacy will not be assured for now the door can be opened from either side.- The inside of the door in the preferred form will bear the legend To insure privacy, turn knob and if this is done, the `rotation of the inside spindle section 44 will cause the top or bottom of the cam 42 depending on the direction of rotation of the knob, to engage the angular lug 51 extending toward the inside lknob from the/outside roll back 50, and this will cause the outside roll back to slide on its,spindle 31 (which is held against rotation `under l such circumstances by the spring 38) so that the tin 53 will enter the slot 60. The springs 34 will hold the outer roll back in Such se-f cured or .caught7 position und'er ordinary jars and rattling of the outer knob, but will otter no appreciable resistance to the return of the outer rollback tothe position shown in Figure 1 by complete forward movement of the bolt.- If in entering the room or compartf ment the inside knob had been turned in either direction the cam 42 would have acted as just described above thus preventing access from without but permitting opening the door from the inside. By substituting an arc 42 for the lower half of the cam 42 (see Figure 5) a further and highly desirable result is secured i. e., the ability to turn the inside knob clockwise (the usual way) and not secure privacy while if it is turned counterclockwise either in closing thedoor or later, the outside knob is held against rotary movement. In such case the legend should read: To insure privacy turn knob to the left.

Movement of the bolt to normal locking position, i. e., as in Figure 4, does not slide the outside roll back to free the lin 53 from the recess 60 but complete forward movement of the bolt always frees this roll back, sliding it forwardly on its spindle 31 to the position of Figure 1. The inner surfaces of the ytwo projections forming the recess 61 are curved to guide the fin 53 to insure that the roll back is held seated against its shank except when in caught position so as to secure the outside knob. If the free end of the bolt is not beveled as is usual this invention insures invariable privacy whenever the door is closed in any way from the inside, but by beveling the bolt end the ability to slam the door shut is secured 'and often this advantage outweighsr the automatic securing of privacy. My 1nvention naturally is not `to be limited by the specic description given but only by the claims following.

What I claim is: K 1. In a latch, a bolt, a spindle composed of independently movable sections, a. bolt operating device on each section, one of said devices bein slidable on its section.

2. In a atch, a bolt, a spindle composed of yoke end, a spindle composed of independently rotatable sections extending between the arms or the yoke, a roll-back on each section to y engage one arm of the yoke, one of said rollbacks being slidable on its section and having an extension to engage in a slot inthe latch casing to prevent rotation of its respective section, and means carried by the otherrollback for sliding the tirstfmentioned roll-back on its section and into locking engagement, complete forward movement or' the bolt treeing the sliding roll-back from locking engagement with the casing while partial'ad- Vance of the bolt does not operate the sliding section;

5. In a latch, a bolt, a spindle composed of independently movable sections, a bolt operating device on each section, and means whereby when the bolt is operated by one section to withdraw the bolt and then move it into normal locked position the other section is locked against rotation, and whereby when the bolt is withdrawn and then moved into normal locked position by the other section the first-mentioned section iS free to withdraw the bolt.

6. In a dead-locking latch, a spring-pressed lOl) bolt, a keeper. having a recessv shallower than the full travel of the bolt, a spindle composed of an 1ns1de sectionand an outside section secured together against relative longitudinal Vmovement but free to rotate independently of one another, means on each section to withdraw the bolt and to release the bolt into full, forward movement not in the keeper or into partial forward movement in the keeper, and means for securing the outside section when the bolt is released into the keeper by the inside section, the bolt being operable from either section when the bolt spring is fully expanded or when the bolt is released i'nto the keeper by movement of the outside section.

7. In a dead-locking latch, a casing having a groove therein, a. spring-pressed bolt slidable in said casing and having a pair of arms forming a yoke, a spindle composed of independently rotatable sections, a roll-back on the outside spindle section adapted to engage either arm of the yoke to withdraw the bolt against its spring, said roll-back being free to slide on its section but constrained to rotate with said section, a fin on said roll-back adapted to engage the groove in said casing to hold said roll-back and its section against rotation, a roll-back on the inside spindle to engage the outside roll-back upon rotation of the inside spindle section to slide the outside lroll-back into locking engagement with said casing, the travel of the bolt being such that when the spring is expanded to the limit of its travel the sliding roll-back is moved out of `locking engagement with the casing but when the bolt is in normal locking position in its keeper the outside spindle section is held against rotation if the latch has last been moved to unlatched position bythe inside spindle section.

8. The device of claim 7 including means resiliently holding the outside roll-backin engagement-with both arms of the yoke and spring means for holding Vsaid last-named means in position to hold the outside shank in a given angular position.

9. In a dead-locking latch, a spring-pressed bolt, a keeper having a recess shallower than the full travel of the bolt, a spindle composed of an inside section' and an outside section free to rotate independently of one another, a roll-back on each section to withdraw the bolt, and means for latching the outside section when the bolt is released into the .keeper by the turning ofthe inside section 1n one direction, the bolt being operable from either section when the bolt is fully extended,

when the bolt is released into the keeper by movement ofthe outside section, or when the bolt is released into the keeper by turning the inside section in one direction.

10. The device of `claim 9 in which the outside spindle section latchingl means includes a cam on the insideroll-back to slide the outside roll-back on the outside section.

11. The device of claim 9 in which the latch casing has a centrally located slot the outside roll-back is slidable on its section and has a fin adapted to enter said slot to latch the outside section against rotation and the inside roll-back has a cam for sliding the outside roll-back to latch the tin in the slot.

12.- In a dead-locking latch, a. springpressed boltI having three positions, the iirst with the bolt,withdrawn into the latch casing, the second with the bolt in latched position in its keeper'and the third with thebolt projected beyond latched position, an outside spindle section, an inside spindle section,

means on each section for moving the bolt from third to Vfirst or second position, means whereby the moving of the bolt from third to second position by the inside section holds the outside section against rotation, and means wherebythe movement of the bolt to third position frees the outside section from such engagement.

13. The device of claim 12 in which when the bolt is in second or normal latched position, the rotation of the inside section in one direction causes the latching of the outsidev section in case the inside section has last been turned in the opposite direction and the outside section is not held against rotation.

14. In a latch, a plurality of bolt .operating devices one of said devices having an ex tended portion and the other device having cam means whereby when the second device is rotated to operate the bolt the first device will be moved awayA from its axis if the angular movement is in one direction but will not be moved at 4all if the angular movement of the second device is in the opposite direction,

ing device against rotation when moved from its axis.

In testimony whereof I aiiix my signature.

HENRY W. KEIGWIN.

l and means for holding the first bolt operat- 

